LOL. I have had the same thing happen in reverse. I was testing the Direct Analog sound versus the A/D and back to D/A circuit in my DSP preamp. I wanted to check there was no degradation to the sound using the DSP built in ADC and DAC (an extra signal path).
Well I forgot to turn off the sub! Since the sub only receives a signal when using ADC and DAC ( no subwoofer output on analog direct) I was A to B comparing music with sub and without it => of course there was a difference!
This really surprised me at first because I was not expecting to hear any difference given the ADC and DAC circuits have distortion specs well below what I know I can detect audibly.
After this surprise and once I remembered to switch off the sub, I could no longer tell whether the extra ADC and DAC was in the circuit or not...but I had a laugh.
Well I forgot to turn off the sub! Since the sub only receives a signal when using ADC and DAC ( no subwoofer output on analog direct) I was A to B comparing music with sub and without it => of course there was a difference!
This really surprised me at first because I was not expecting to hear any difference given the ADC and DAC circuits have distortion specs well below what I know I can detect audibly.
After this surprise and once I remembered to switch off the sub, I could no longer tell whether the extra ADC and DAC was in the circuit or not...but I had a laugh.